Glazing and polishing machine



April 25, 1950 F. R. WHITCOMB 2,505,223

" GLAZING AND POLISHING MACHINE I Filed Feb. 26, 1947 I 3 Sheets-Sheet l 25 Z2 0 0 o 24 4h 1 vi *7 o IN VEN TOR.

F. R. WHITCOMB GLAZING AND POLISHING MACHINE April 25, 1950 Filed Feb. 26. 1947 5 Shets-Sheet 2 cull-E51 ll R V mm m X i V H u 1. N

BY I yam-W1 HYDRAULIC PUMP April-25,1950 2 RR WHITCOMB 2,505,223

GLAZING AND ousgmc MACHINE Filed Feb. 26, 1947 3 S1 1eets-Sheet 3 106 I I v 62 10s 110 INVENTDR. firms?" .Elrdievamb operation of the lifting and traversing mechanism. Independent regulation of the speed of operation of the work-supporting traverse bar 22 in the work head 25 is secured by provision of a manually-operated regulating valve V F: in the supply line for the master valve V2. If no traverse is desired, the valve V6 is closed.

A pressure cylinder C3 acts to absorb hydraulic shock at the moment of reversal of the work head, which head is of substantial weight.

A differential valve V8 controls the flow of liquid to the left-hand end of the cylinder C which swings the rolls R toward and away from the work. A reversing valve V9 is associated with the difierential valve V8 and is shifted at the upper and lower limits of work travel by dogs 40 and 4!, adjustably secured on an upright bar 42 secured to the work head 25 and vertically reciprocated therewith.

The upper dog 40 engages shifting pins 44 (Fig. 1) on the-inner face of a segmental plate 45 associated with the valve V9, and the lower dog 4| similarly engages pins 46 on the outer face of the disc 45. The dogs and pins are so arranged that either dog, after reversing the valve V9, may freely continue its travel in the same direction and without damage to the valve- .shifting mechanism.

The pressure of the rolls R on the work W may be varied by a cam plate 50 (Fig. 2) associated .with the movable bar 42 and vertically reciprocated therewith. The cam plate 58 engages one farm of a bell crank 52 mounted on a fixed pivot The outer end of the other arm of the bell crank engages the head 54 (Fig, 4) of a plunger 55 forming a part of the differential valve V8.

A balancing valve Vlt (Figs. 3 and 5) is provided to supply increased back pressure below the piston 28 to offset the weight of the work head and associated parts during downward movement thereof. Differential valve The valve V8 which controls the operation of the'cylinder C in moving the rolls R toward and away from the work is of special construction,

the details of which are clearly shown in Fig. 4.

. The valve V8 'is connected to the reversing valve V9 by a pipe 60 and is connected through a pipe Bl to the left-hand end of the rollpositioning cylinder C. The opposite end of the cylinder 0 is directly connected to the reversing valve V9 through a pipe 62. I

Assuming that the rolls R are to be advanced The oil then flows through a passage 67 to a recess 68 and past an open valve 10 to a chamber H, from which the oil flows through a passage E2 to the pipe 6| leading to the left-hand end of the chamber C. As the farms M and it are substantially on dead center in vertical position, only extremely light oil pressure is needed to advance the rolls to engage the work.

As soon as such engagement takes place, how

ever, the resistance to further advance movement of the rolls causes the pressure to increase in the various passages of the difierential valve V8.

This increased pressure acts against a piston 13 and depresses the piston against the resistance of a spring '14. As the piston '13 is thus moved downward, the valve 10, previously held raised by the piston rod 15, is moved downward by gravity and a light spring 76 and closes the direct connection between the recess 68 and the chamber 1 i. I

the needle valve 85 to the passage 3| Oil from the supply pipe til thereafter travels from the recess 68 through a by-pass to a passage Bl which is connected at one end to the chamber H and at the opposite end to a passage 82 which opens into an exhaust connection 83. Flow of oil from the recess 68 to the by-pass 80 is controlled by a needle valve 85 which has a head 86 for manual adjustment.

The connection between the passage 8| and the exhaust passage 82 is controlled by the plunger 55 previously described. This plunger has a beveled lower end, as shown in Fig. 4, and is yieldingly raised by a spring 99 against the pressure of the bell crank 52 (Fig. 2).

In the operation of the cylinder C to advance the rolls R toward each other, there is an initial and substantially free flow of oil past the valve 70 until the rolls engage the work, whereupon the pressiue rises, due to resistance to further roll advance. This increased pressure closes the valve 79, and there is then restricted flow past A part of the oil flowing into the passage Si is delivered through the chamber 'il and pipe 6! to the cylinder C, and a part of the oil escapes past the plunger 55 to the exhaust pipe 83.

The ratio of oil delivery between the pipes 6| and 83 is determined by the position of the beveled plunger 55, which in turn is determined by the cam plate 50. As the cam plate moves upward and downward with the work, the position of the plunger 55 may be varied as desired to correspond with the varying contour of the work or to any variation in the work area engaged at a given point by the rolls R. As the work head 25 approaches its limit of travel in either direction, the reversing valve V9 is actuated by a dog 40 or ll to reverse the connections to the valve V8 and the cylinder C through the pipe 60 and 52, so that the pipe 62 then becomes the suppl pipe and the pipe 6| becomes the exhaust pipe.

Liquid exhausted from the left-hand end of the cylinder C then flows upward through the pipe 6| (Fig. 4) and lifts the check valve 56, thus provid ing a direct connection of substantial capacity to the pipe 68, which is now the exhaust pipe. The valve 10 also opens to provide additional exhaust capacity. Consequently the movement of the rolls R away from the work is very rapidly performed.

Balancing value The construction of the Valve Vlll which balances the work head 25 is shown in Fig. 5. Oil from the master valve V3 is delivered to the valve VII] through a pipe 92, and the valve is connected to the lower end of the lifting cylinder C through a pipe 93. The valve VH1 comprises an upwardly opening valve member which is normally seated and closed by a relatively heavy spring 95. A

downwardly opening valve member 91 is mounted in an axial passage 98 in the valve member 95 and is normally closed by a light spring 99.

When the pipes 82 and 93 act collectively to supply oil to the lower end of the cylinder C for raising the piston 28 (Fig. 3) and the work head 25, the oil flows freely downward through the axial passage 98 in the valve member 95 and around the lightly loaded valve member 97, which readily yields to downward pressure.

When the pipes 92 and 93 act collectively to exhaust the lower end of the cylinder C during downward movement of the work head 25 and piston 28, the valve 91 will be closed by the oil pressure and will then act'as a-check valve. Ihe

ou er.- valverinembertimustr hen be littedzag;

he .elative vaheavvisprinei9T ...thusmai e ni a .relatively eavvbackzpressurei ,thellower o the-svlmderfl' durirlswdownward ravel of 1 th w rk head. This arran ement: takest are of h substantialdifferencelin load duringupwardand ownwa d movements-of.- the; heavy work; head 25..

Reversing: valve The reversing valve N9, is, of special constructionand is sodesigned-that'movement1oi the Segmental. plate-45 in either direction item normal position Joy-.a vdog- 4u-'01':4l;"wi11' reverse the oil connections-tombs valve V 8, and to. the .cylindenC andswill move therollsRapartatreversal.of work travel in either direction. :Assoon astravel thereatterbegins inthe-reverse direction-by operation of. the valve VA thesame dog 40hr Mv will-return the valve-Vll to normal position and-willthusinn mediately restore the l-zydraulic connections. to the v operative condition necessary .ior applying essur o h o ls,

The details of construction of the uaIve VS -are clearly shown, in Eigssfiato 9. The valve, VdiEig.

fi-)- tcomprises .abase 1 00, "a cap 1.0! .and .a disc end, the-stud. H?! hasarhead l 18 provided witha cross ribJ 1.9;. Asupply pipe GAE-1 3?) from the .pumpJPis connected through a passage l2 lto the cylindrical reeessvor chamber 1 ti whieh is always under pressure.

The disc-member J02 -Eig..&,-)- hasports [30,13]

7 and 1.32. extending .therethrough and also has; an

exhaust recess I35 z-provided'w-ith. arms I36, 13,! and 3 8. Shallow recesses MD are provided: in the face of the disc member JflZi-tQ- reduce friction, and the pressurein :these areas is relieved by bleed openings 1 4.1. i

The discmemloerillZ (Fig. 6) has a-groove M4 in its outer surtacetowreceive the cross rib 4.1-9 previouslydescri-bed; :so that the d-isc member 02 amlv segmental. plate 45,: will-rotate together.

The. parts are shown. in .Fig. 6' in position. to supply pressure. to th .pipefiin. and. valv VH press the rolls R against the WQrk. Inthisposi- 'tion, thep 1 .0. n e d sc member I02 is aligned with the port I I0. in the base [00,, 50 that oil under pressure suppliedthrou'gh thepipe 12E] (Fig. 8) to the pressure chamber H5 will be delivered to the pipe tn connecting to the 'difierenti-al valve V8; The valve V8 "then supplies oil through the pipe 61 to the left-hand end of the cylinder .0, and the rolls R are thus advanced and pressed against the Work.

At the same time thepipe 62 from the right.- hand end of the cylinder 6 connected through the recess H4 and port 412 to the arm- 136 of the exhaust recess ld-Eyand thusthrough the exhaust passage M6 to the exhaust; pipe 19.1,. This isithenormal or running position pith-e parts.

If the plate 45 and the valve. member 1.2 are displaced in either direction by a dog, #10: or H.

one efethepor s l or; l32 w1l1 connect; t e-pres.-

erehamb r -I. '5. hr h e. p H in he base othapi 6. ..t us applvi gpre u -in the ri htnd end of" the cylinder-C t0 separate the rolls *At' the:-sametime-one of the arms I31 or Edd-ofthe-exhaust recess [:35 will be aligned with the port l'30',thus connecting the left-hand endofthe cylinder; C through the diiiferentia-l valvervsr-and pipe 6M0 exhaust.

The valve V9 thus-provideshydraulic-connections topress the rolls R against the workwhen the-valve is in-normalor mid position, and-providesconneotionsto quickly separate therolls andrelease the pressure on the work Whenever the 'segmental disc'45is displaced in either di rection atthe end of; work travel by a dog 40; or 41. .A-springmressed'ball [5B (Fig. 6) holds the valveVQ yieldingly in mid-position if at any time it is not held by-oilpressure and friction. Valve .VAL may be turnedqnanua-lly 180 to render'the valve inoperative when automatic pressure-re lie s notwrequired.

Operation Having-described the-details of construction of my improved machine, the operation thereof is as follows: I k

The work W is suspended-:from the traverse rod 2;2 and-receiv.es limited and-relatively-slow traversing movements, mainly for distributing the wear on the polishing rolls. These traversing movements are effected by the cylinder 0-2 under control of the master valve V which in turn is controlledby thereversing; valve V2 operated by dogs--32 on the;traversebar 22-. This traversing operation is continuous so -long as the pump P is in opera-tion-and the throttle valve V5 is open. The speed of the traversingmotion is controlled by the regulating valve V6 which. may also be used to stopall traverse.

The work head =25. which carries the worksupporting -traverse rod-Z-Zfls vertically reciprocated by the --cylinder C" which alternately res eeives. oil under pressure-at its upper and lower ends by operationofthe, master valve V3. -Duringdownward movement,the weight of the work head and associated reciprocating parts is balanced by increasedbackpressure in the valve VH3.

The master valvevaiscontrolled by the reversingvalve V4, whichisalternately shifted angularlyby fingers 35. on the rod-'36 which is verticallyr-eciprocated with-thework head. The upper and lower fingers 35-control normal travel of the work-"head and thelower finger 35l-imits upward over-run. This ever-run is accomplished by manually shifting thear-ms titan-d (7'4 of the valve V4. axially. Further movement of the same shifting lever (not shown) closes the throttle valve V5-to stop. the machine-at any desired. point.

Thecylinder G3-acts as a shock abserber and prevents hydraulic knock as the work head is reversed at the end ofits travel.

The rolls R are moved toward and away from the work by-theveyh-nder 6 under the control of the, d-iiferential valve Ve and the reversing valve V9. The valve V9, as previously described, normany-maintains pressure in the pipe 60 to move the rolls toward ac eth nd o app y p ssur tothe work. The valve V9 isshifted at the upper and lower ends or normal travel by the dogs 40, and 4t, and when so. shiftedapplies pressure through the pipe 62 lie-separate the rolls R.

The pinS,44sar1d: l-; 6 on the segmental plate 45 are so arranged that the same dog, which shifts ha'va v o t of; normal po t on wi m diat return the valve to normal position as soon as the return movement of the work head and do begins. Consequently the rolls R are moved away from the work at both extreme limits of travel and are returned to again engage the work as soon as reverse travel begins. This prevents engage ment of the rolls with the work during the time of reversal when the work is substantially motionless. Otherwise lines or shadows would be produced in the finished surfaces.

The pressure of the rolls against the work during the travel of the work is controlled and may be varied by the cam plate 59 which moves vertically with the work head and which varies the position of the plunger 55 in the valve V8 through the medium of the bell crank 52. Movement of the plunger 55 varies the flow to the exhaust pipe 83 and reversely varies the flow to the pipe 6! connected to the roll-operating cylinder C.

The cam plate 50 may be made with any desired taper or with a contoured surface, so that the pressure may be varied to correspond with the work area in contact with the rolls at any given point in the vertical reciprocation of the work. This variable control of the roll pressure against the work is extremely important and enables me to produce glazed and mirror surfaces of very unusual quality.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is: I 1. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coacting work-engaging rolls, means to press said rolls against the work, and means to vary the pressure of the rolls against the work in predetermined relation to the work travel during the finishing operation thereon and while the rolls remain in engagement with the work.

2. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coacting work-engaging rolls, means to press said rolls against the work, and means to relieve the roll pressure as the work head approaches each end of its locus of reciprocation and during reversal thereof and while the rolls remain in engaging relation with the work.

3. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coacting work-engaging rolls, means to press said rolls against the work, and means to relieve the roll pressure as the work head approaches each end of its locus of reciprocation and during reversal thereof and while the rolls remain in engaging relation with the work and to restore the roll pressure as the reverse movement begins.

4. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coacting work-engaging rolls, means to advance said rolls to engage the work with very light pressure, and means to thereafter increase the roll pressure on the work during the finishing operation thereon and while the rolls remain in engagement with the work.

5. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coacting work-engaging rolls, means to advance said rolls to engage the work with very light pressure, and means to increase the roll pressure as the work is engaged by the rolls and to vary the roll pressure during the work travel and in predetermined relation thereto.

6. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coacting work-engaging rolls, means to advance said rolls to engage the work with very light pressure, means to increase the roll pressure as the work is engaged by the rolls, and means to entirely relieve the roll pressure at each end of each reciprocating movement of the work during the finishing operation thereof and while the rolls remain in engaging relation with the work.

7. In a glazing and polishingmachine, a pair of work-engaging rolls, hydraulic means to press said rolls against the work and including a hydraulic by-pass connection, manual means to control the flow through said by-pass connection, and automatic means to vary the roll pressure by bleeding said by-pass connection.

8. In a glazing and polishing machine, a pair of work-engaging rolls, hydraulic means to press said rolls against the work and including a hydraulic by-pass connection, and automatic means to vary the roll pressure by bleeding said by-pass connection and in predetermined relation to the work travel. 9. In a glazing and polishing machine, a pair of work-engaging rolls, hydraulic means to press said rolls against the work, a supply of liquid under pressure for said hydraulic means, and a differential device effective to reduce the operating pressure of said liquid.

10. In a glazing and polishing machine, a pair of work-engaging rolls, hydraulic means to press said rolls against the work, a supply of liquid under pressure for said hydraulic means, a differential device effective to reduce the operating pressure of said liquid, and automatic means to vary the setting of said differential device.

11. In a glazing and polishing machine, a pair of work-engaging rolls, hydraulic means to press said rolls against the work, a supply of liquid under pressure for said hydraulic means, a differential device effective to reduce the operating pressure of said liquid, and manual means to vary the flow of liquid to said differential device.

12. In a grinding and polishing machine, a reversing valve having supply and exhaust connections and two operating connections, and a valve member movably mounted in said valve and provided with ports and with an exhaust recess, said ports and said exhaust recess being so disposed that displacement of said valve from normal position in either direction will reverse the relation of said operating connections to said supply and exhaust connections.

13. In a grinding and polishing machine having a work head and hydraulic means including a cylinder and piston to vertically reciprocate said head, in combination, means to balance the weight of the reciprocated parts on the down stroke comprising a back-pressure valve in the pipe which is connected to the end of the cylinder which is exhausted on said down stroke, said valve having a valve member opening under relatively light pressure towardsaid cylinder and'a second valve member opening under'relatively heavy pressure away from said cylinder.

14. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coacting work-engaging rolls, means to press said rolls against the work, means to relieve the roll pressure as the work head approaches each end of its locus of reciprocation and to restore the roll pressure as the reverse movement begins, and means to vary the pressure of the rolls against the work in predetermined relation to the work travel and during the finishing operation on the work.

15. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coacting work-engaging rolls, means to press said rolls against the work, cam means reciprocated with the Work head and controlling the roll pressure on the work in predetermined relation to the work travel, and means to relieve the roll pressure as the work head approaches each end of its locus of reciprocation and to restore the roll pressure as the reverse movement begins.

16. In a glazing and polishing machine, a work head, means to reciprocate said head, a pair of coaoting work-engaging rolls, hydraulic means to press said rolls against the work, differential means to control the flow of the hydraulic liquid, and means to relieve the roll pressure as the work head approaches each end of its locus of reciprocation and to restore the roll pressure as the reverse movement begins.

1'7. A glazing and polishing machine as set forth in claim 16, in which the differential control means includes a valve member which is variably positioned in predetermined relation to the reciprocation of the work.

18. In a glazing and polishing machine, a valve mechanism comprising a feeding connection to admit operating liquid to said machine, means REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,123,171 Hamilton July 12, 1938 2,269,311 Johnson Jan. 6, 1942 2,287,559 Nye June 23, 1942 2,390,495 Caldwell Dec. 11, 1945 FOREIGN PATENTS Number Country Date 87,921 Austria Apr. 10, 1922 

